Aaron Pixton : Divisors on the moduli space of stable n-pointed curves of genus 0

Posted by , part of the Algebraic Geometry Seminar.

At

Nov. 16, 2011, 4 p.m.

In

SEO 427

Abstract

I'll discuss various conjectures about divisors on $\overline{M}_{0,n}$ and describe a counterexample to one of them: it is not true that every nef divisor is numerically equivalent to an effective sum of boundary divisors. The counterexample is combinatorial in nature and is closely related to the (11, 5, 2) biplane.